Wood stoves, particularly log-burning stoves, are often unsatisfactorily designed for the loading and burning of heavy logs. U.S. Pat. No. 4,131,104, issued Dec. 26, 1978, discloses an improved log-burning stove, wherein the stove door has been modified to provide for a plurality of free-wheeling rollers in the plane of the stove door, whereby heavy logs may be placed on the roller surface and positioned easily in front of the combustion-chamber opening, when the stove door is open, and then the log may be introduced into the combustion chamber by rolling the log or by raising the stove door.
U.S. patent application Ser. No. 962,042, filed Nov. 20, 1978 (hereby incorporated by reference) and which is a continuation-in-part of the application which matured into U.S. Pat. No. 4,131,104, discloses a further improvement in log-burning wood stoves, particularly in the design of the stove door. The improved log-burning stove includes a stove door leading to a combustion chamber, which door comprises a plurality of spaced-apart, generally parallel, raised, fixed rib elements on the interior of the stove door. The design and construction of the rib elements in the stove door were designed and serve to strengthen the door and to provide an upper surface of the rib elements upon which the heavy logs may be slid easily in position and introduced into the combustion chamber; for example, by raising the stove door from the open, extended to the closed position.
While the improved log-burning stove represents an advance in the art, it has been found in practice that the use of the fixed rib elements on the stove door may have certain disadvantages under high heat conditions. The fixed rib elements served, firstly, to strengthen the stove door, and, secondly, to provide at least two central rib elements or ways for the sliding of the heavy logs. It has been discovered that, in this particular construction, wherein the stove door opens from top to bottom; that is, extends horizontally outwardly from the lower section of the combustion opening in use, the top of the stove door tends to become quite hot during operation of the stove, and particularly where an elongated draft opening is employed under the bottom of the door, as set forth, for example, in U.S. Pat. No. 4,154,211, issued May 15, 1979. The difference in temperature between the top and the bottom of the stove door has been found to create a twisting force, due to the difference in expansion of the fixed rib elements secured to the door surface, which twisting force may warp the stove door. Further, inquiry has indicated that the fixed rib elements, which usually are welded to the door along the full length thereof for strength purposes, projected more inwardly than the outer peripheral door frame, and, thus, tended to be closer to the flame of the combustion chamber and to expand linearly slightly more than the door frame, which may compound the disadvantages associated with the difference in temperature between the top and bottom of the stove door.
Thus, it is desired to provide an improved log-burning wood stove which will overcome the disadvantages recited and to permit heavy logs to be positioned and introduced into the combustion chamber, without causing any damage to the stove door.